Fusible switch



1,508,035 w. a. UNDERWOOD FUSIBLE SWITCH Sept. 9, 1924.

F1106 Alli- 1922 2 Sheets-Shut 1 BY pi 5/5 ATTORNEYS.

Sept. 9, 1924. 1,508,035

' W. B. UNDERWOOD FUSIBLE SWITCH Filld Aug. '9, 1922 2 Sheets-Shoot 2 INVENTOR. Weecieiz Z3, Hilda/0000!) %za ATTORNEYS.

Patented Sept. 9, 1924.

UNITED STATES 1,508,035 PATENT OFFICE.

WEI-DEN B. UNDERWOOD, O1 ROCHESTER, NEW YORK, ASBIGNOB TO WILKOT CASTLE COMPANY, OF ROCHESTER, NEW YORK. A CORPORATION OF NEW YORK.

FUSIBLE SWITCH.

Application filed August 9, 1922. Serial No. 580,787.

To all whom it may omwern:

Be it known that I, WEEDEN B. UNDER- woon, a citizen of the United States, and resident of Rochester, in the county of Monroe and State of New York, have invented certain new and useful Improvements in Fusible Switches, of which the following is a specification.

The present invention relates to heated containers and more particularly to the type in which a heating element is employed having controllinga'means which antomatically cut oil the cat source when the heat in the container becomes excessive. An object of this invention is to provide a bottom wall with a depression or channel adjacent the side walls of the container for maintaining a liquid adjacent the side walls when the main portion of the bottom wall becomes dry, so that the joint or connection between the bottom wall and the side walls will not become loosened by heat applied to the 'main portion of the bottom wall. Another object of the invention is to provide an improved fusible resisting means for a heat controlling means which moves automatically to cut off heat to the con- .tainer whenever excessive heat occurs in the container.

To these and other ends, the invention consists of certain parts and combinations of parts, all of which will be hereinafter described, the novel features being pointed out in the appended claims.

In the drawin Fig. 1 is a side view of a container embodying the present invention;

Fig. 2 1s a bottom view of such a container Fig. 3 is a fragmentary section on the line 3-3, Fig. 2;

Fig. 4 is a fragmentary section on the line 44, Fig. 3;

Fig. 5 is a sectional view of the fuse device showing the manner of supporting the receptacle in which the fusible material is arranged 5 1 Fig. 61s a fra mentary sectional view of the manner in w ich the snap-switch operating slide or motor connects with the snapswitch, the latter being shown in closed po- Fi 7 is a similar view of the snapswitc in open position.

Referring more particularly to the embodiment herein illustrated, 1 indicates a vessel or receptacle which, in this instance, has its side walls formed from sheet metal, said side walls extending upwardly from legs 2 secured by welding or otherwise to the side walls at the corners thereof, and sald side walls having also inwardly proecting ribs 3 on which a bottom wall 4 is supported, said bottom wall being soldered to the side walls to .prevent any leaks. This bottom wall has an upwardly extendmg central portion 5 spaced from the side walls of the receptacle on all sides and providing a pocket 6 on the under side of the bottom wall. A heating means such as an electrical heatin element 7 of any construction is arrange in the ocket 6 and is insulated from the bottom y insulation 8. A plate 9 is bolted to the bottom at 10 and is insulated from the heating element 7 by insulation 11. This plate 9 also has integral lugs 12, depending therefrom and connected at their lower ends by a bridge piece 13 which is secured in place by screws 14. The bridge piece serves as a support for a snap switch casing 15 formed of insulating material and carrying two contacts 16 connected with terminals and adapted also to be connected by an oscillatory switch member 18, which is normally in closed position and is automatically shifted to open position whenever the heat in the container becomes excessive. The details of this snap switch form no part of the present invention.

The operating member 19 forming art of the snap switch extends upwardly -om the casing and into a recess 20 in a slide or motor member 21 which is guided in openings 22 formed in the two de nding portions 12 of the plate 9, said sli e lying in engagement with the upper surface of the bridge plate 13. This slide has a stem 23 extending through a side wall of the container 1 below the bottom 4 and the end of the stem is provided with a finger iece 24 by which the slide may be presse inwardly. A helical spring 25 surrounds the spring 23 between the wall of the container 1 and the finger piece 24 and causes the slide to move in the opposite direction to tion of the sp cessive heat occurs in the container 1, the slide is provided with a spring detent 26 and the end of this detent is adapted to co- 7 operate with ratchet or stop teeth 27 formed on the end of a receptacle 28, this receptacle being supported at its lower end on a screw 29 in the bridge piece 13, and being extended upwardly through an opening 30 in the supporting plate 9 to receive within its open upper end a tapered projection 31 formed on the bot-tom of the bottom plate 4. Within the receptacle, a readily fusible material 32' is contained and projectin in this readily fusible material 32 is an anc oring member or stem 33, which is secured at its upper end to the bottom 5, preferably in the tapering projection 31 on said bottom. This stem has two cylindrical centering portions 33 and 33' which fit the walls of the receptacle and tend to hold the latter in a centered position. The stem also has a toothed portion 33 between the teeth of which the fusible material 32 passes, in order to establish a connection between the stem and the fusible material and prevent the stem from turning in said fusible material. When the fusible material is hard,

it connects the stem 33 with the rotary receptacle 28 and holds such receptacle against turning, so that the latter through the ratchet or stop teeth 27 will hold the slide or motor member in a position where the snap switch is closed, as shown in Fig. 6. However, when exee'ssive'heat occurs 1n the container 1, this fusible material 32 will soften and permit the receptacle 28 to turn and the slide or motor member 19 to move under theinfluence. of the spring 23, thus shifting the snap switch to' open position, as shown in Fi 7.

The current is delivered to the appliance by means of line wires 34 and 35, the former connecting with one of theterminals of the snap switch 18. From the other terminal of the snap switch 18, a conductor 36 leads to the four terminal snap switch 19 which connects with the line wire 35 and also with three terminals 37, 38 and 39 of the heating unit, the heating unit be ing so formed that portions thereof may be cut out by the four terminal snap switc 19 to vary the amountof heat obtained from such unit.

The operation of the illustrated embodiment of the invention is as follows: Assuming that the slide or motor member 21 has been pressedinwardly against the ac g 23, the detent 26 will cooperate with the ratchet or stop wheel 27 and hold the motor member against its normaltendency to move inthe opposite direction. In this position, the motor member holds the snap switch 18 closed, .as ilh lustrated in Fig. 6. Should the container become-' ver-heated, due to the driving of h I the container,

the liquid therefrom, except that within the channel about the side walls, the fusible material 32 will melt and the rotar receptacle 28 will turn relatively to t e stem 33 under the action of the spring 23, thus permitting the slide or motor member 21 to move to open the switch, as shown in Fig. 7, and cutting of? the current to the heating element.

From the foregoing it will be seen that there has been provided an electrically heated container in which the bottom wall is soldered to the side walls and is provided with a channel adjacent said soldered joint to hold liquid, after the central portion of the bottom becomes dry or overheated under the action of the heating element, thus permitting the heat of the central. ortion to be communicated to the fusib e device which restrains the movement of the motor member that acts to cut oil the current to' the electrical heating means. The fusible device is of novel construction and em ies a rotary receptacle containing the fusible material and in which a stem depends from the bottom of the container. What I claim as my invention and desire to secure by Letters Patent is:

1. An electrically heated container having a bottom soldered to the side walls thereof and provided with a central upwardly projecting portion spaced from the side walls to provide a channel in proximity to the side walls the central upwardly projecting portion having a pocket in its underside, heat ng means having an electrical heating element arranged in the pocket and provided with means havin a normal tendency to out 01f the'heat, and a fuse device for restraining such tendency, subject to the influence of the central ortion of the bottom of the conductor, so that when said central portion becomes dry, such fuse device will release the controlling means before the li]? s uid in the channel adjacent the side wa is evaporated;

2. The combination with a container having a bottom, of a stem depending from said bottom, a rece tacle rotatably mounted and containing a sible material in which the stem depends to lock the receptacle to the stem, a heating means for the contents of and means having a normal tendency tocut oif said heating means and restrained by said rota container.

. 3. The combination with a container having a bottom, of a depending stem" on said bottom, acylindrical portion on said stem, a rotary receptacle having fusible material therein in which the stem'depends to lock the receptacle to the stem, said container fitting said cylindrical portion, means for eating the contents of the container, and means for 'eontrollin the heating means aving a normal ten ency to cut of the heating means and restrained by the rotary container.

4. The combination with a container having a bottom, of an electrical heating element arranged under said bottom and insulated therefrom, a plate secured to said bottom over said heating element, and insulated therefrom, two posts depending from said plate, a bridge piece connecting said posts, a stem depending from said bottom, a receptacle supported by said bridge piece and containing a fusible element in which said stem depends, a switch for controlling said electrical heating element, and means for moving said switch having a normal tendency to move to open the switch, and restrained by said receptacle containing the fusible material.

5. The combination with a container, of

a heating element supported at the bottom of said container, and two elements, one of which is rigidly secured to the bottom and the other of which is rotatably mounted below said bottom, one of said elements being in the form of a receptacle containing a fusible material in which the other element projects.

6. The combination with a container, of a heating element supported by the container, and controlling means for the heating element embodying two elements, one of which is held against turning and the other of which is supported to turn, one of said elements being in the form of a receptacle containing a fusible material in which the other element projects to lock the two elements to ther.

WEE EN B. UNDER-WOOD. 

